Slip the Mustang up through the gears as you hit a winding country road, or zip onto the freeway and you feel totally in command. The car grumbles and roars, its Eaton M122 blower boosting the car up to 60+ mph in a blink. Ford says 0-60 in 4.2 seconds with a top speed of 155 mph, limited by a governor.

Mustang’s rear-drive wheels dig in and push the car hard, thanks to 20-inch Goodyear Eagle F1 SuperCar G:2 tires in back and 19 inchers in front. The tires are low-profile and fat to give you super grip, which is their point. But the cost is in ride quality, which is severe on our crumbling Midwestern roads.

Steering is highly responsive with no lean or push in a corner. Much of that steering precision is due to a new electric power assist system. With the Shelby you stay flat and smooth.

Like most cars of this price and quality, the Mustang comes standard with traction control and stability control too along with four-wheel disc brakes. There’s even a slotted brake dust shield to help improve cooling, if you’re pushing those brakes to the limit, most likely on a racetrack.

Note that the test car also upped the ante with a $3,495 SVT Performance package that adds the upgraded Goodyear tires, plus performance tuned shocks and stiffer springs, plus a special spoiler in back with a Gurney Flap to improve high-speed handling. Is all this necessary in everyday driving? No, but if you intend to race your Mustang, these are gotta-haves.

I wasn’t racing but did make a highway drive to Chicago and back. I managed an impressive 21 mpg on the drive, with about 80% being highway miles. Back in town I hit 20.1 mpg in about 65% highway miles and I was not babying the accelerator. The EPA says the Mustang will average about 15 mpg city and 23 highway, which means there is no gas guzzler tax as the car had in the past. In fact, this is better than you’ll get in a less powerful SUV that’s not nearly so much fun to drive.

As much as I love the Shelby GT’s looks and performance, the interior has a few issues, although its styling overall is still fun and youthful.

This one had black leather seats with white stitching and twin red racing stripes in the cushions, plus suede inserts on the side bolsters and a similar material on the steering wheel for added grip and comfort. It feels great.

I like the three-spoke steering wheel, too, and the white cue-ball shifter that adds just a touch of retro look. What I’m not so wild about is the tilt-only steering wheel. At this price I’d expect a telescoping feature, too.

I also don’t care for the large stereo speakers in the doors. They protrude too much and sometimes make it a little difficult to turn and get your feet out of the car once you finish your drive. That’s less of a problem if you’re not in a tight parking lot where you can swing the door to its full open position. And lastly, I’ve seen a lot of fake carbon fiber and cool textured metallic trim on sporty car dashes, but this is not among them. The pattern here is little polka dots and looks pretty cheesy.

Those complaints aside, the interior works well from a functional point. The wheel, for instance, has cruise

The Shelby’s seats are incredibly comfortable with tall side bolsters to hold a driver snuggly in place. Support is good, with moderately firm cushions so you could enjoy a long drive. These are powered seats too, including a power lumbar support for the driver. Head and legroom are good up front, but limited in back. If you’re a taller driver, don’t count on anyone being able to sit behind you.

Mustang’s dash gauges are large and easy to see and the controls simple to use while driving. Three buttons on the dash’s left control the trip computer and there’s a touch-screen for the navigation system and radio. As with all car touch screens though, you frequently have to hit a button a second time to get it to react.

As with most Ford products now, the Shelby comes with the Microsoft Sync system to hook up and coordinate all your electronic devices so you can activate them by voice. And while I didn’t care for the big speakers in the doors, the stereo sounded great.

The Shelby’s base price is $48,645 with an $850 delivery charge. Add in all the goodies on this one and it hit $55,330.

That’s a lot. So if your checking account is a little thinner like mine, consider both the Mustang GT with a romping 412-horse V8 or a base model with a 305-horsepower V6. They start at $29,645 and $22,145, respectively and both are great fun and look nearly as beautiful as the Shelby.

No matter the trim the 2011 Mustang is muscle car perfection, and a muscle car lover’s dream.